%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%% datatypes.sty %%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% Commands Provided:
%%
%%   \DECLARETYPE{Foo}
%%   \DECLARESUBTYPE{Foobar}{Foo}
%%
%%   \PRESETS{Foobar}{STUFF}
%%   \POSTSETS{Foobar}{STUFF}
%%
%%   \MAP{Foobar}{OPTION}
%%   \SURFACEMAP{Foobar}{OPTION}
%%   \REMAP{Foobar}
%%   \RESURFACEMAP{Foobar}
%%   \CHANGEMAP{Foobar}{OPTION}
%%   \CHANGESURFACEMAP{Foobar}{OPTION}
%%
%%   \NEW{Foobar}{\command}{STUFF}
%%   \INSTANCE{Foobar}{STUFF}{OPTION}
%%   \EVERY{Foobar}{OPTION}
%%
%%     Available in "STUFF" and "OPTION":
%%
%%     \MYTYPESTRING
%%     \MYPARENTSTRING
%%     \MYCOMMAND
%%     \ME
%%     \MYMAP
%%     \PARENT
%%     \PARENTMAP
%%     \PARENTSURFACEMAP
%%
%%     \F \field
%%     \FD \field {defaultval}
%%     \FS \field {val}
%%     \s \field {val}
%%     \rs \field {val}
%%     \sd \field {defaultval}
%%     \append \field {val}
%%     \prepend \field {val}
%%
%%     \ADD{STUFF}
%%     \RESET
%%
%%   \toss[num]{stuff}
%%
%%   \SORT{Foobar}{sort}{field}{Datatype macros}{OPTION}
%%   \MAKESORT{Foobar}{sort}{field}{Datatype macros}{NAME}
%%   \USESORT{Foobar}{NAME}{OPTION}
%%
%%     options for "sort":
%%       num<
%%       num>
%%       alpha<
%%       alpha>
%%       ascii<
%%       ascii>
%%
%%   \SIFT{Foobar}{sift}{field}{value}{Datatype macros}{OPTION}
%%   \MAKESIFT{Foobar}{sift}{field}{value}{Datatype macros}{NAME}
%%   \USESIFT{Foobar}{NAME}{OPTION}
%%
%%     options for "sift":
%%       =
%%       !=
%%       num<
%%       num>
%%       num<=
%%       num>=
%%       alpha<
%%       alpha>
%%       alpha<=
%%       alpha>=
%%       ascii<
%%       ascii>
%%       ascii<=
%%       ascii>=
%%
%%%%%


%%%%%
%% allowing ":" to be used in TeX command names, for this file, so
%% "internal" commands that use it can't be used directly/messed
%% with outside of this file.
\catcode`\:11\relax


%%%%%
%% Datatypes act like "Classes" in object oriented programming.  They
%% can "inherit" parent types ("superclasses").  Datatype macros are
%% effectively "objects" or "instances" of the given Datatype.
%%%%%


%%%%%
%% \:rf return first
%% \:df delete first

%% lots of things use this
\def\:singletst{\futurelet\:tmp\::singletst}
\long\def\::singletst#1#2\:delim{\def\:tmp{#2}}

%% defines \:tmp to be the first value
\def\:rf#1{%
  \long\def\:tmp\:i##1##2\:delim{\def\:tmp{##1}}%
  \ifx#1\empty\else\expandafter\:tmp#1\:delim\fi}

%% removes first value
\def\:df#1{%
  \long\def\:tmp\:i##1##2\:delim{\def#1{##2}}%
  \ifx#1\empty\else\expandafter\:tmp#1\:delim\fi%
  \def\:tmp{}}

%% generic append
\long\def\:ap#1#2{%
  \expandafter\edef\expandafter#1\expandafter{%
    \expandafter\unexpanded\expandafter{#1#2}}}

%% appends #2 to #1 using command #3 (\global or \relax)
\long\def\::al#1#2#3{%
  \def\:tmp{#2}%
  \unless\ifx\:tmp\empty
    \:singletst#2\:delim%
  \else%
    \let\:tmp\relax%
  \fi%
  \ifx\:tmp\empty%
    #3\:ap#1{\:i#2}%
  \else%
    #3\:ap#1{\:i{#2}}%
  \fi}

%%%%%
%% \:typetest{string}{definition}
\long\def\:typetest#1#2{%
  \edef\:tmp{#1}\ifx\:tmp\empty\er:tblank\let\:tmp\empty\else%
  \ifcsname#1:t\endcsname%
    \edef\:ti{\csname#1:t\endcsname}%
    \edef\:pi{\csname\csname\:ti :p\endcsname :t\endcsname}%
    #2%
  \else%
    \er:tunknown{#1}\let\:tmp\empty%
  \fi\fi}


%%%%%
%% \toss[num]{stuff}
%% \stoss{stuff}
%% \etoss{stuff}
%% \preprocess{stuff}
\def\toss{\futurelet\:nxt\:toss}
\def\:toss{%
  \ifx\:nxt[\def\:nxt{\::toss}%
  \else\def\:nxt{\::toss[1]}%
  \fi\:nxt}
\long\def\::toss[#1]#2{%
  \ifnum#1<0\relax%
  \else\ifnum#1=0\relax%
    \def\:nxt{#2}%
  \else\ifnum#1=1\relax%
    \def\:nxt{\etoss{#2}}%
  \else%
    \:count=#1\advance\:count by-1\relax%
    \expandafter\def\expandafter\:nxt\expandafter{\expandafter\stoss%
      \expandafter{\expandafter\::toss\expandafter[\the\:count]{#2}}}%
  \fi\fi\fi\:nxt}

\def\stoss{\:eqaf}
\long\def\etoss#1{\:toks{}\start:aft#1\end:aft}
\long\def\preprocess#1{\begingroup\etoss{#1}\endgroup}

\def\?{\let\:sptoken= }\?
\def\:ob{{\iffalse}\fi}
\def\:cb{\iffalse{\fi}}

\def\:clear{%
  \ifx\:nxt?\let\:nxt\:suckQ\else\let\:nxt\relax\fi\:nxt}
\def\:suckQ#1{\?}

\def\:norm:aft{%
  \def\?{\futurelet\:nxt\:clear}%
  \long\def\X##1{##1}%
  }
\def\:in:aft{%
  \def\?{\?}%
  \long\def\X{\X}%
  }
\:norm:aft

\def\end:aft{\end:aft}%
\def\end::aft{\end::aft}%
\def\start:aft{\:in:aft\futurelet\:nxt\:aft}
\def\:aft{\let\:tmp\relax%
  \ifx\:nxt\:sptoken\def\:tmp{\:dospace}%
  \else\ifx\:nxt\bgroup\def\:tmp{\:dogrp}%
  \else\ifx\:nxt\end:aft\def\:tmp{\:doend}%
  \else\ifx\:nxt\end::aft\def\:tmp{\::doend}%
  \else\ifx\:nxt\?\def\:tmp{\:doquery}%
  \else\ifx\:nxt\X\def\:tmp{\:doprotect}%
  \else\def\:tmp{\:dotok}%
  \fi\fi\fi\fi\fi\fi\:tmp}
\def\:dospace#1 {\:toks\expandafter{\the\:toks\space}\start:aft}
\long\def\:dogrp#1{%
  \def\:tmp{#1}%
  \ifx\:tmp\empty\else\:singletst#1\:delim\fi%
  \ifx\:tmp\empty\let\:tmp#1\else\let\:tmp\empty\fi%
  \ifx\:tmp\bgroup\:toks\expandafter{\the\:toks\noexpand#1}%
  \else%
    \:toks\expandafter{\the\:toks\:ob}%
    \start:aft#1\end::aft%
    \:toks\expandafter{\the\:toks\:cb}%
  \fi\let\:tmp\relax\start:aft}
\def\:doend#1{%
  \edef\:tmp{\the\:toks}%
  \:toks{}%
  \edef\:tmp{\:tmp}%
  \expandafter\:eqaf\expandafter{\:tmp}%
  \def\:tmp{}}
\def\::doend#1{\:norm:aft}%
\def\:doquery#1{\futurelet\:nxt\::doquery}
\def\::doquery{%
  \ifx\:nxt?\def\:nxt##1{\:toks\expandafter{\the\:toks\noexpand\?}\start:aft}%
  \else\long\def\:nxt##1{%
    \expandafter\start:aft\expandafter\X\expandafter{##1}}%
  \fi\:nxt}
\long\def\:doprotect#1#2{%
  \:toks\expandafter{\the\:toks\unexpanded{#2}}\start:aft}
\long\def\:dotok#1{\:toks\expandafter{\the\:toks\noexpand#1}\start:aft}

%% \:eqaf
%% \:dqaf
\gdef\:qnum{-1}
\gdef\:qlst{}

\long\def\:eqaf#1{%
  \ifx\:qlst\empty%
    \:count=\:qnum\relax%
    \advance\:count1%
    \xdef\:qnum{\the\:count}%
    \expandafter\def\expandafter\:nxt\expandafter{\csname :q\:qnum\endcsname}%
  \else%
    \:rf\:qlst%
    \let\:nxt\:tmp%
    \:df\:qlst%
    \global\let\:qlst\:qlst%
  \fi%
  \expandafter\xdef\:nxt{\unexpanded{#1}}%
  \aftergroup\:dqaf\expandafter\aftergroup\:nxt}

\def\:dqaf#1{%
  \def\:tmp##1{%
    \expandafter\def\expandafter\:tmp\string\:q####1\:delim{\def\:tmp{####1}}%
    \expandafter\:tmp\string##1\:delim}%
  \:tmp#1%
  \:count=\:qnum%
  \advance\:count-1%
  \ifnum\:count=\:tmp%
    \xdef\:qnum{\the\:count}%
  \else%
    \::al\:qlst#1\global%
  \fi%
  \let\:tmp#1%
  \global\let#1\relax%
  \:tmp}


%%%%%
%% \DECLARETYPE{Foo}
%% Creates a new Datatype, with "Foo" as the typestring.
\def\DECLARETYPE#1{\DECLARESUBTYPE{#1}{}}


%%%%%
%% \DECLARESUBTYPE{Foobar}{Foo}
%% Creates a new Datatype "Foobar" with Datatype "Foo" as the "parent"
%% Datatype.  "Inherits" the contents of Foo's \PRESETS and \POSTSETS,
%% is included in the list of \EVERY{Foo}, and by default, Foobar macros
%% are initially mapped to an equivalent of \PARENTMAP.
\def\:tc{0}
\def\DECLARESUBTYPE#1#2{%
  \def\:tmp{#1}\ifx\:tmp\empty\er:tblank%
  \else\ifcsname#2:t\endcsname%
    \ifcsname#1:t\endcsname%
      \:typgenwarn{Datatype "#1" is already defined.\:mb Command ignored.}%
    \else%
      \expandafter\edef\csname#1:t\endcsname{\:tc}%
      \:count\:tc%
      \advance\:count1%
      \edef\:tc{\the\:count}%
      \expandafter\let\expandafter\:ti\csname#1:t\endcsname%
      \expandafter\let\expandafter\:pi\csname#2:t\endcsname%
      \expandafter\ifx\csname\:ti :p\endcsname\empty%
        \expandafter\def\csname\:ti :pdo\endcsname{%
          \:typwarn{\string\PARENT: "#1" has no parent.}}%
        \expandafter\def\csname\:ti :phd\endcsname{%
          \:typwarn{\string\PARENTMAP: "#1" has no parent.}}%
        \expandafter\def\csname\:ti :phh\endcsname{%
          \:typwarn{\string\PARENTSURFACEMAP: "#1" has no parent.}}%
      \else%
        \csname\:pi :ca\endcsname{#1}%
        \begingroup%
          \aftergroup\def\expandafter\aftergroup\csname\:ti :pdo\endcsname%
          \aftergroup{\aftergroup\let\aftergroup\PARENT%
            \expandafter\aftergroup\csname\:pi :pdo\endcsname%
            \expandafter\aftergroup\csname\:pi :rdo\endcsname%
            \aftergroup\let\aftergroup\PARENT%
            \expandafter\aftergroup\csname\:ti :pdo\endcsname\aftergroup}%
        \endgroup%
        \begingroup%
          \aftergroup\def\expandafter\aftergroup\csname\:ti :phd\endcsname%
          \aftergroup{\aftergroup\let\aftergroup\PARENTMAP%
            \expandafter\aftergroup\csname\:pi :phd\endcsname%
            \expandafter\aftergroup\csname\:pi :rhd\endcsname%
            \aftergroup\let\aftergroup\PARENTMAP%
            \expandafter\aftergroup\csname\:ti :phd\endcsname\aftergroup}%
        \endgroup%
        \begingroup%
          \aftergroup\def\expandafter\aftergroup\csname\:ti :phh\endcsname%
          \aftergroup{\aftergroup\let\aftergroup\PARENTSURFACEMAP%
            \expandafter\aftergroup\csname\:pi :phh\endcsname%
            \expandafter\aftergroup\csname\:pi :rhh\endcsname%
            \aftergroup\let\aftergroup\PARENTSURFACEMAP%
            \expandafter\aftergroup\csname\:ti :phh\endcsname\aftergroup}%
        \endgroup%
      \fi%
      \expandafter\def\csname\:ti :p\endcsname{#2}%
      \expandafter\def\csname\:ti :ct\endcsname{}%
      \begingroup%
        \aftergroup\def\expandafter\aftergroup\csname\:ti :ca\endcsname%
        \aftergroup##\aftergroup1\aftergroup{%
          \aftergroup\::al\expandafter\aftergroup\csname\:ti :ct\endcsname%
          \aftergroup{\aftergroup##\aftergroup1\aftergroup}\aftergroup\relax%
          \expandafter\aftergroup\csname\:pi :ca\endcsname%
          \aftergroup{\aftergroup##\aftergroup1\aftergroup}\aftergroup}%
      \endgroup%
      \expandafter\def\csname\:ti :lst\endcsname{}%
      \begingroup%
        \aftergroup\def\expandafter\aftergroup\csname\:ti :add\endcsname%
        \aftergroup##\aftergroup1\aftergroup{%
          \aftergroup\::al\expandafter\aftergroup\csname\:ti :lst\endcsname%
          \aftergroup##\aftergroup1\aftergroup\relax%
          \expandafter\aftergroup\csname\:pi :add\endcsname%
          \aftergroup##\aftergroup1\aftergroup}%
      \endgroup%
      \expandafter\expandafter\expandafter\def\expandafter\expandafter%
      \csname\:ti :pre\endcsname\expandafter{\csname\:pi :pre\endcsname}%
      \expandafter\expandafter\expandafter\def\expandafter\expandafter%
      \csname\:ti :pst\endcsname\expandafter{\csname\:pi :pst\endcsname}%
      \MAP{#1}{\PARENT}%
    \fi%
  \else%
    \:typgenerr{Datatype "#2" isn't defined; hence it can't\:mb be
      used as a parent for datatype "#1."}{Declare "#2" before
      declaring any children.}%
  \fi\fi}


%%%%%
%% Datatype macros each contain a set of "STUFF" that effectively gets
%% executed inside the macro (inside a TeX group) every time it is used.
%%
%% The "STUFF" comes in the following order:
%%
%%    (parenttype's \PRESETS "STUFF")
%%    \PRESETS "STUFF"
%%    "STUFF" from \NEW
%%    (parenttype's \POSTSETS "STUFF")
%%    \POSTSETS "STUFF"
%%
%%  The "STUFF" from \NEW is unique to each macro, unlike the rest,
%%  which is the same for all macros of a given Datatype.
%%
%%  For all "STUFF" unnested (La)TeX command definitions need not use
%%  doubled #'s for args (i.e. don't treat commands with "STUFF" as
%%  TeX macro definitions).
%%%%%


%%%%%
%% \PRESETS{Foobar}{STUFF}
%% Sets \PRESETS "STUFF" for Datatype Foobar 
\long\def\PRESETS#1#2{\:typetest{#1}{%
  \expandafter\:ap\csname\:ti :pre\endcsname{#2}%
  }}


%%%%%
%% \POSTSETS{Foobar}{STUFF}
%% Sets \POSTSETS "STUFF" for Datatype Foobar 
\long\def\POSTSETS#1#2{\:typetest{#1}{%
  \expandafter\:ap\csname\:ti :pst\endcsname{#2}%
  }}


%%%%%
%% Datatype macros take a single argument (_required_braces_), that
%% is "OPTION."  "OPTION" is expanded inside the macro, effectively
%% right after all of "STUFF."  So, any defined macros in "STUFF" are
%% available (i.e. a field declared in \PRESETS with "\F \somefield"
%% and set in \NEW with "\s \somefield {somevalue}" can be used in
%% "OPTION").
%%
%% If "OPTION" is blank (i.e. "\sometypemacro{}" not "\sometypemacro{ }")
%% the current "mapping" of the Datatype is expanded instead (changed by
%% \MAP, etc).
%%
%% In "OPTION," the same (non-)rules apply to nesting macro definitions
%% as for "STUFF."
%%
%% In both "STUFF" and "OPTION" the following commands are available:
%%
%%   \MYTYPESTRING -> i.e. "Foobar" for Foobar Datatypes
%%   \MYPARENTSTRING -> i.e. "Foo" for Foobar Datatypes
%%   \MYCOMMAND -> the command name for the Datatype Macro
%%   \ME -> same as \MYCOMMAND for normal macros, see "\INSTANCE" below
%%   \MYMAP -> the mapping of the Datatype (only available in "OPTION")
%%   \PARENT -> parenttype's mapping
%%%%%

\long\def\CHILDTYPES#1#2{%
  \edef\:dotypes{\unexpanded{#2}}%
  \def\:i##1{\def\TYPE{##1}\:dotypes}%
  \expandafter\csname\csname#1:t\endcsname :ct\endcsname%
  \let\TYPE\empty}

\long\def\BRANCHTYPES#1#2{%
  \edef\:dotypes{\unexpanded{#2}}%
  \def\:i##1{\def\TYPE{##1}\:dotypes}%
  \:i{#1}%
  \expandafter\csname\csname#1:t\endcsname :ct\endcsname%
  \let\TYPE\empty}


%%%%%
%% \MAP{Foobar}{OPTION}
%% Sets the mapping of Foobar Datatypes to "OPTION"
\long\def\MAP#1#2{\:typetest{#1}{%
  \CHANGEMAP{#1}{#2}%
  \CHANGESURFACEMAP{#1}{#2}%
  \REMAP{#1}%
  }}


%%%%%
%% \SURFACEMAP{Foobar}{OPTION}
%% "Temporarily" sets the mapping of Foobar Datatypes.
%% The current mapping is stored, and the mapping is reset to it for
%% Foobar macros _nested inside_ Foobar macros, i.e. \SURFACEMAP's
%% mapping only applies to the "first level" (present level) of Foobar
%% macro nesting.
%%
%% Repeated uses of \SURFACEMAP only change the \FISTMAP mapping, not the
%% stored mapping.  \MAP changes both the current mapping and the stored
%% mapping and "turns off" the effects of \SURFACEMAP.
\long\def\SURFACEMAP#1#2{\:typetest{#1}{%
  \CHANGESURFACEMAP{#1}{#2}%
  \RESURFACEMAP{#1}%
  }}


%%%%%
%% \REMAP{Foobar}
%% "Turns off" the effect of \SURFACEMAP, i.e. restores the current
%% mapping to the stored mapping.
\long\def\REMAP#1{\:typetest{#1}{%
  \expandafter\expandafter\expandafter\def\expandafter\expandafter%
  \csname\:ti :do\endcsname\expandafter{\csname\:ti :rhd\endcsname}%
  }}


%%%%%
%% \RESURFACEMAP{Foobar}
\long\def\RESURFACEMAP#1{\:typetest{#1}{%
  \expandafter\expandafter\expandafter\def\expandafter\expandafter%
  \csname\:ti :do\endcsname\expandafter{\csname\:ti :rhh\endcsname}%
  }}


%%%%%
%% \CHANGEMAP{Foobar}
\long\def\CHANGEMAP#1#2{\:typetest{#1}{%
  \expandafter\edef\csname\:ti :hd\endcsname{\unexpanded{#2}}%
  }}


%%%%%
%% \CHANGESURFACEMAP{Foobar}
\long\def\CHANGESURFACEMAP#1#2{\:typetest{#1}{%
  \expandafter\edef\csname\:ti :hh\endcsname{\unexpanded{#2}}%
  }}


%%%%%
%% Datatype macros, which act like "objects" or "instances" of
%% Datatypes, can be created by \NEW.  \NEW can include "STUFF" which
%% is unique to the given macro.
%%
%% When a Datatype macro is created as such, it is added to a list of
%% macros for the given Datatype, which is accessible via \EVERY.  If
%% a Datatype has a parenttype, macros of that Datatype are also added
%% to the \EVERY list of the parent Datatype.
%%
%% With \INSTANCE, it is possible to create and use, at the same time, a
%% single, unique, and temporary "instance" of a Datatype.  "STUFF" for
%% \INSTANCE would substitute for "STUFF" in an equivalent use of \NEW,
%% while "OPTION" would work the same as for a macro created by \NEW,
%% so \INSTANCE{Foobar}{STUFF}{OPTION} would have similar effect to
%% \NEW{Foobar}{\temp}{STUFF} \temp{OPTION}.  However, it does not
%% create an actual macro.  This "temporary instance" is not added to
%% any \EVERY list.
%%%%%


%%%%%
%% \NEW{Foobar}{\command}{STUFF}
%% Creates \command{} as a Foobar macro, with "STUFF"
\def\:ic{0}
\long\def\NEW#1#2#3{\:typetest{#1}{%
  \ifdefined#2%
    \:typgenerr{"\string#2" is already defined.}{"\string#2" is
      already defined (by \string\def, \string\newcommand, etc).\:mb
      Or it may be a default (La)TeX macro.  Or it may already be a
      \:mb datatype macro.  A datatype macroname must be unique.}%
  \else%
    \csname\:ti :add\endcsname#2%
    \expandafter\let\csname\string#2:ic\endcsname\:ic%
    \expandafter\def\csname\:ic :l\endcsname{}%
    \expandafter\edef\csname\:ic :pr\endcsname{%
      \noexpand\:prep{\:ic}{#1}\noexpand#2{\unexpanded{#3}}}%
    \expandafter\edef\csname\:ic :o\endcsname{%
      \unexpanded{\let\:opt\empty}\csname\:ic :op\endcsname}%
    \expandafter\edef\csname\:ic :op\endcsname{%
      \noexpand\futurelet\noexpand\:nxt\csname\:ic :opt\endcsname}%
    \expandafter\edef\csname\:ic :opt\endcsname{%
      \unexpanded{\ifx\:nxt[\let#2}\csname\:ic :opti\endcsname%
      \unexpanded{\else\let#2}\csname\:ic :optio\endcsname%
      \noexpand\fi\noexpand#2}%
    \expandafter\edef\csname\:ic :opti\endcsname[##1]{%
      \noexpand\def\noexpand#2{\expandafter\noexpand\csname\:ic :o\endcsname}%
      \noexpand\:ap\noexpand\:opt{##1}%
      \expandafter\noexpand\csname\:ic :op\endcsname}%
    \expandafter\edef\csname\:ic :optio\endcsname##{%
      \noexpand\def\noexpand#2{\expandafter\noexpand\csname\:ic :o\endcsname}%
      \csname\:ic :c\endcsname}%
    \edef#2{\expandafter\noexpand\csname\:ic :o\endcsname}%
    \long\expandafter\edef\csname\:ic :c\endcsname##1{%
      \noexpand\begingroup\expandafter\noexpand\csname\:ic :pr\endcsname%
      \noexpand\:doarg{#1}{##1}\noexpand\endgroup}%
    \:count\:ic%
    \advance\:count1%
    \edef\:ic{\the\:count}%
  \fi%
  }}


\long\def\:EXTEND#1{\:typgenerr{Don't use \string\EXTEND on non Datatypes.}%
  {It has no context.}}

\long\def\::EXTEND#1{%
  \endgroup\expandafter\:ap\csname\:id :l\endcsname{#1}%
  \begingroup}

\def\:optionfix{\long\def\OPTIONHOOK##1{##1}}
\long\def\EXTEND#1#2{#1[\:optionfix]{\:EXTEND{#2}}}


\long\def\:prep#1#2#3#4{%
  \:count\:lvl%
  \advance\:count1%
  \edef\:lvl{\the\:count}%
  \edef\:ti{\csname#2:t\endcsname}%
  \long\def\OPTIONHOOK##1{##1}%
  \def\MYTYPESTRING{#2}%
  \edef\MYPARENTSTRING{\csname\:ti :p\endcsname}%
  \def\MYCOMMAND{#3}%
  \let\::opt\:opt%
  \ifx\::opt\empty%
    \let\ME\MYCOMMAND%
  \else%
    \expandafter\def\expandafter\ME\expandafter{%
      \expandafter#3\expandafter[\::opt]}%
  \fi%
  \def\MYMAP{\:mydo}%
  \stoss{\def\:id{#1}}%
  \expandafter\let\expandafter\PARENT\csname\:ti :pdo\endcsname%
  \expandafter\let\expandafter\PARENTMAP\csname\:ti :phd\endcsname%
  \expandafter\let\expandafter\PARENTSURFACEMAP\csname\:ti :phh\endcsname%
  \let\F\:F%
  \let\FD\:FD%
  \let\FS\:FS%
  \let\s\:s%
  \let\rs\:rs%
  \let\sd\:sd%
  \let\append\:append%
  \let\prepend\:prepend%
  \edef\:presentfont{\the\font}\nullfont%
  \let\::par\par\let\par\relax%
  \csname\:ti :pre\endcsname%
  #4%
  \csname#1:l\endcsname%
  \::opt%
  \csname\:ti :pst\endcsname%
  \let\par\::par\:presentfont%
  \let\ADD\:ADD%
  %\def\RESET{\:reset}%
  \let\:EXTEND\::EXTEND%
  }

\long\def\:remap#1{%
  \expandafter\expandafter\expandafter\let\expandafter\expandafter%
  \csname\:ti :rdo\endcsname\csname\:ti :do\endcsname%
  \expandafter\expandafter\expandafter\let\expandafter\expandafter%
  \csname\:ti :rhd\endcsname\csname\:ti :hd\endcsname%
  \expandafter\expandafter\expandafter\let\expandafter\expandafter%
  \csname\:ti :rhh\endcsname\csname\:ti :hh\endcsname%
  \expandafter\ifx\csname\:ti :p\endcsname\empty%
    \BRANCHTYPES{#1}{\REMAP{\TYPE}}%
  \else%
    \edef\:tmp{\csname\:ti :p\endcsname}%
    \edef\:ti{\csname\:tmp :t\endcsname}%
    \expandafter\:remap\expandafter{\:tmp}%
  \fi}

\long\def\:doarg#1#2{%
  \edef\:tmp{\unexpanded{#2}}%
  \ifx\:tmp\empty%
    \:remap{#1}%
    \edef\:ti{\csname#1:t\endcsname}%
    \expandafter\let\expandafter\:mydo\csname\:ti :rdo\endcsname%
    \def\:tmp{\MYMAP}%
  \fi\expandafter\OPTIONHOOK\expandafter{\:tmp}}


%%%%%
%% \INSTANCE{Foobar}{STUFF}{OPTION}
%% Creates a temporary instance of Foobar, with "STUFF" and "OPTION."
%% For a use of \INSTANCE{Foobar}, \MYCOMMAND only corresponds to
%% "\INSTANCE{Foobar}," i.e. not enough information to recreate the
%% complete uniqueness of the use of \INSTANCE.  \ME, however, is defined
%% as "\INSTANCE{Foobar}{STUFF}."
%%
%% Like macros created by \NEW, braces for "OPTION" are required, even
%% if "OPTION" is blank (TeX gives an error if there are no braces).
\long\def\INSTANCE#1#2{\:typetest{#1}{%
  \expandafter\def\csname :\:lvl\endcsname##1{%
    \:count\:lvl%
    \advance\:count1%
    \edef\:lvl{\the\:count}%
    \edef\:ti{\csname#1:t\endcsname}%
    \long\def\OPTIONHOOK####1{####1}%
    \def\MYTYPESTRING{#1}%
    \edef\MYPARENTSTRING{\csname\:ti :p\endcsname}%
    \def\MYCOMMAND{\INSTANCE{#1}}%
    \let\::opt\:opt
    \ifx\::opt\empty%
      \def\ME{\INSTANCE{#1}{#2}}%
    \else%
      \edef\ME{\unexpanded{\INSTANCE{#1}{#2}}%
        [\expandafter\unexpanded\expandafter{\::opt}]}%
    \fi%
    \def\MYMAP{\:mydo}%
    \expandafter\let\expandafter\PARENT\csname\:ti :pdo\endcsname%
    \expandafter\let\expandafter\PARENTMAP\csname\:ti :phd\endcsname%
    \expandafter\let\expandafter\PARENTSURFACEMAP\csname\:ti :phh\endcsname%
    \let\F\:F%
    \let\FD\:FD%
    \let\FS\:FS%
    \let\s\:s%
    \let\rs\:rs%
    \let\sd\:sd%
    \let\append\:append%
    \let\prepend\:prepend%
    \edef\:presentfont{\the\font}\nullfont%
    \let\:par\par\let\par\relax%
    \csname\:ti :pre\endcsname%
    #2##1\::opt%
    \csname\:ti :pst\endcsname%
    \let\par\:par\:presentfont%
    %\long\def\ADD####1{\endgroup\begingroup\csname :\:lvl\endcsname{####1}}%
    \long\def\ADD####1{####1}%
    %\def\RESET{\endgroup\begingroup\csname :\:lvl\endcsname{}}%
    \long\def\:EXTEND####1{}%
    }%
  \long\def\:tmp##1{%
    \begingroup\csname :\:lvl\endcsname{}\:doarg{#1}{##1}\endgroup}%
  }\INSTANCE:}
\def\INSTANCE:{\let\:opt\empty\INSTANCE::}%
\def\INSTANCE::{\futurelet\:nxt\INSTANCE:::}
\def\INSTANCE:::{\ifx\:nxt[\def\:nxt{\INSTANCE::::}%
  \else\def\:nxt{\INSTANCE:::::}\fi\:nxt}%
\def\INSTANCE::::[#1]{\:ap\:opt{#1}\INSTANCE::}%
\def\INSTANCE:::::#{\:tmp}%


%%%%%
%% \EVERY{Foobar}{OPTION}
%% Effectively executes the entirety of the the "\EVERY list" for the
%% given Datatype, all with "OPTION" i.e. has same result as using all
%% the macros, in order created, with "OPTION" explicitly (not faked
%% with mappings).
\long\def\EVERY#1{\def\:tmp{#1}\EVERY:}
\def\EVERY:{\futurelet\:nxt\EVERY::}
\def\EVERY::{\ifx\:nxt[\def\:nxt{\EVERY:::}
  \else\def\:nxt{\EVERY:::[]}\fi\:nxt}
\long\def\EVERY:::[#1]{\def\:opt{#1}\EVERY::::}
\def\EVERY::::#{\expandafter\EVERY:::::\expandafter{\:opt}}
\long\def\EVERY:::::#1#2{\:typetest{\:tmp}{%
  \ifx\:opt\empty%
    \def\:i##1{\:ap\:tmp{##1{#2}}}%
  \else%
    \def\:i##1{\:ap\:tmp{##1[#1]{#2}}}%
  \fi%
  \def\:tmp{\let\:tmp\empty}\csname\:ti :lst\endcsname}\:tmp}


%%%%%
%% Within Datatypes, the following commands are used to declare, set,
%% and manipulate "fields."  Fields are essentially basic TeX macros,
%% i.e. are expanded the same.  These commands are a good way to set up
%% error checking to catch typos, declare fields that must be explicitly
%% set before being used, set things with defaults, catch accidentally
%% setting them twice, etc.
%%
%% \F, \FD, and \FS are for declaring a field.  They set internal flags
%% (separate from the actual field) that say the field exists as a field
%% and label which nesting level the field belongs to (so Datatype macros
%% nested inside one another, with matching field names, can avoid
%% conflicts).  These flags are also used to determine whether or not
%% a field is declared with a "default" or has been explicitly set.
%%
%% \F declares a field, with no value.
%%
%% \FD declares a fields with a "default."
%%
%% \FS declares a field and explicitly sets it.
%%
%% \s, \rs, \append, and \prepend are for setting and manipulating
%% a field; they use the internal flags.
%%
%% \s explicitly sets the field to a value, and gives a warning (not an
%% error; it does the set anyway) if the field was already set (if it
%% was only a "default" no warning is given, if it was already explicitly
%% set, even to exactly the same as the default, it does warn).
%%
%% \rs explicitly sets the field, and doesn't give a warning if it has
%% already been explicitly set (i.e. a "reset").
%%
%% \append and \prepend explicitly set the field by "adding" the given
%% value to the end or beginning of the field, respectively.  If the
%% field has _not_ been explicitly set (default or no), they just
%% explicitly set the field to the value, i.e. they ignore and replace
%% a "default" value.
%%
%% In general, errors happen when a field is declared with a command
%% name that is already a field or (La)TeX macro, if a field is used
%% before having any value, or if \s, \rs, etc. are used on something
%% that has not been declared a field.
%%%%%


%%
\def\:deferr#1#2{
  \:typerr%
    {\string#1 in "\string#2\string#1" in
    \expandafter\noexpand\MYCOMMAND\:mb is already defined.}%
    {\string#1 is already defined (by \string\def, \string\newcommand,
    etc).  \:mb Or it may be a default (La)TeX macro.  Fields must be
    unique.}}%
\def\:fielderr#1#2{
  \:typerr%
    {\string#1 in "\string#2\string#1" in
    \expandafter\noexpand\MYCOMMAND is already a field.}%
    {\string#1 is already declared by \string\F, \string\FD, or
    \string\FS.  Fields must be unique.}}%
\def\:noferr#1#2{
  \:typerr%
    {\string#1 in \expandafter\noexpand\MYCOMMAND has not been
    declared a field.}%
    {"\string#2\string#1" may just be a typo in
    \expandafter\string\MYCOMMAND. Otherwise, \string#1 needs to be
    \:mb declared by "\string\F\string#1" (or \string\FD, or
    \string\FS).}}%


%%%%%
%% \F \field
%% Declares a field "\field" with no default (must be set before it is
%% expanded or it gives an error).  Effectively defines the macro as the
%% error.
\def\:F#1{%
  \:gofalse%
  \ifdefined#1%
    \ifcsname\string#1.w\endcsname%
      \ifcsname\:ti\string#1\:lvl\endcsname%
        \:fielderr{#1}{\F}%
      \else%
        \:gotrue%
      \fi%
    \else%
      \:deferr{#1}{\F}%
    \fi%
  \else%
    \:gotrue%
  \fi%
  \if:go%
    \expandafter\def\csname\:ti\string#1\:lvl\endcsname{y}%
    \expandafter\let\csname\string#1.w\endcsname\empty%
    \def#1{\er:funset{#1}}%
  \fi}


%%%%%
%% \FD \field {defaultval}
%% Declares \field with "defaultval" as the value, and sets the internal
%% flag to say the value is a "default."
\long\def\:FD#1#2{%
  \:gofalse%
  \ifdefined#1%
    \ifcsname\string#1.w\endcsname%
      \ifcsname\:ti\string#1\:lvl\endcsname%
        \:fielderr{#1}{\FD}%
      \else%
        \:gotrue%
      \fi%
    \else%
      \:deferr{#1}{\FD}%
    \fi%
  \else%
    \:gotrue%
  \fi%
  \if:go%
    \expandafter\def\csname\:ti\string#1\:lvl\endcsname{y}%
    \expandafter\let\csname\string#1.w\endcsname\empty%
    \def#1{#2}%
  \fi}


%%%%%
%% \FS \field {val}
%% Declares \field, and explicitly sets it to "val"
\long\def\:FS#1#2{%
  \:gofalse%
  \ifdefined#1%
    \ifcsname\string#1.w\endcsname%
      \ifcsname\:ti\string#1\:lvl\endcsname%
        \:fielderr{#1}{\FS}%
      \else%
        \:gotrue%
      \fi%
    \else%
      \:deferr{#1}{\FS}%
    \fi%
  \else%
    \:gotrue%
  \fi%
  \if:go%
    \expandafter\def\csname\:ti\string#1\:lvl\endcsname{y}%
    \expandafter\def\csname\string#1.w\endcsname{y}%
    \def#1{#2}%
  \fi}


%%%%%
%% \s \field {val}
%% Explicitly sets \field to "val" and gives a warning (but does it
%% anyway) if the \field has already been explicitly set.
\long\def\:s#1#2{%
  \ifdefined#1%
    \ifcsname\:ti\string#1\:lvl\endcsname%
      \expandafter\ifx\csname\string#1.w\endcsname\empty\else%
        \:typwarn{\string#1 in \expandafter\noexpand\MYCOMMAND is
          \noexpand\s more than once.}%
      \fi%
      \def#1{#2}%
      \expandafter\def\csname\string#1.w\endcsname{y}%
    \else%
      \:deferr{#1}{\s}%
    \fi%
  \else%
    \:noferr{#1}{\s}%
  \fi}


%%%%%
%% \rs \field {val}
%% Explicitly sets \field to "val"
\long\def\:rs#1#2{%
  \ifdefined#1%
    \ifcsname\:ti\string#1\:lvl\endcsname%
      \def#1{#2}%
      \expandafter\def\csname\string#1.w\endcsname{y}%
    \else%
      \:deferr{#1}{\rs}%
    \fi%
  \else%
    \:noferr{#1}{\rs}%
  \fi}


%%%%%
%% \sd \field {default}
%% sets \field default to "default"
\long\def\:sd#1#2{%
  \ifdefined#1%
    \ifcsname\:ti\string#1\:lvl\endcsname%
      \expandafter\ifx\csname\string#1.w\endcsname\empty%
        \def#1{#2}%
      \fi%
    \else%
      \:deferr{#1}{\sd}%
    \fi%
  \else%
    \:noferr{#1}{\sd}%
  \fi}


%%%%%
%% \append \field {val}
%% Explicitly sets \field by appending "val" to the end of the previous
%% expansion of \field.  If field has not been explicitly set before,
%% it just explicitly sets it to "val" (possibly replacing a "default").
\long\def\:append#1#2{%
  \ifdefined#1%
    \ifcsname\:ti\string#1\:lvl\endcsname%
      \expandafter\ifx\csname\string#1.w\endcsname\empty%
        \edef#1{\unexpanded{#2}}%
      \else%
        \:ap#1{#2}%
      \fi%
      \expandafter\def\csname\string#1.w\endcsname{y}%
    \else%
      \:deferr{#1}{\append}%
    \fi%
  \else%
    \:noferr{#1}{\append}%
  \fi}


%%%%%
%% \prepend \field {val}
%% Explicitly sets \field by prepending "val" to the beginning of
%% the previous expansion of \field.  If field has not been explicitly set
%% before, it just explicitly sets it to "val" (possibly replacing a
%% "default").
\long\def\:prepend#1#2{%
  \ifdefined#1%
    \ifcsname\:ti\string#1\:lvl\endcsname%
      \expandafter\ifx\csname\string#1.w\endcsname\empty%
        \def#1{#2}%
      \else%
        \edef\:tmp{\unexpanded{#2}}%
        \expandafter\:ap\expandafter\:tmp\expandafter{#1}%
        \let#1\:tmp%
      \fi%
      \expandafter\def\csname\string#1.w\endcsname{y}%
    \else%
      \:deferr{#1}{\prepend}%
    \fi%
  \else%
    \:noferr{#1}{\prepend}%
  \fi}



%%%%%
%% For a Datatype macro, commands etc. in "OPTION" are not "remembered"
%% from use to use of the macro, and the rest of "STUFF" in the macro
%% are either declared for all macros of that Datatype or declared once
%% for that macro by \NEW.  Therefore, inside macros, the following
%% commands are available that allow commands etc. to be "remembered"
%% from use to use, effectively allowing "mutability."
%%
%% \ADD and \GLOBALADD add things to the stored "memory" of "STUFF"
%% for the Datatype macro they are used in.  \RESET and \GLOBALRESET
%% cause that "remembered STUFF" to be blanked out.
%%%%%


%%%%%
%% \ADD{STUFF}
%% Adds "STUFF" to the "remember STUFF" for the macro it is used in.
%% "STUFF" also takes effect immediately.
\long\def\:ADD#1{%
  #1\expandafter\EXTEND\expandafter{\ME}{#1}%
  \expandafter\stoss\expandafter{\expandafter\EXTEND\expandafter{\ME}{#1}}}
%  \endgroup%
%  \expandafter\:ap\csname\:id :l\endcsname{#1}%
%  \begingroup%
%  \csname\:id :pr\endcsname}


%%%%%
%% \RESET
%% Blanks out the "remembered STUFF" for the macro it is used in.  Also
%% "restarts" the use of the Datatype macro, such that things declared,
%% set, or defined etc. so far local to the macro no longer have effect
%% (i.e. "\FS \field {blah} \RESET \field" will give the error that
%% "\field" is an undefined control sequence).
%\def\:reset{%
%  \endgroup%
%  \expandafter\def\csname\:id :l\endcsname{}%
%  \begingroup%
%  \csname\:id :pr\endcsname}


%%%%%
%% \SORT{Foobar}{sort}{field}{Datatype macros}{OPTION}
%%
\long\def\SORT#1#2#3#4#5{\:typetest{#1}{%
  \:checksortarg{#2}%
  \let\:tmp\relax%
  \if:go%
    \:dosort{#1}{#2}{#3}{#4}%
    \def\:i##1{\:ap\:tmp{##1{#5}}}%
    \def\:tmp{\let\:tmp\empty}%
    \:sorted%
    \global\let\:sorted\relax%
  \fi%
  }\:tmp}


%%%%%
%% \MAKESORT{Foobar}{sort}{field}{Datatype macros}{NAME}
%%
\long\def\MAKESORT#1#2#3#4#5{\:typetest{#1}{%
  \:checksortarg{#2}%
  \if:go%
    \ifcsname#5:SORT\endcsname%
      \:typgenwarn{"#5" reused as sorted list name.}%
    \fi%
    \:dosort{#1}{#2}{#3}{#4}%
    \expandafter\let\csname#5:SORT\endcsname\:sorted%
    \global\let\:sorted\relax%
  \fi%
  }}


%%%%%
%% \USESORT{NAME}{OPTION}
%%
\long\def\USESORT#1#2{%
  \ifcsname#1:SORT\endcsname%
    \def\:i##1{\:ap\:tmp{##1{#2}}}%
    \def\:tmp{\let\:tmp\empty}%
    \csname#1:SORT\endcsname%
    \global\let\:sorted\relax%
  \else%
    \def\:tmp{\:typgenwarn{sorted list "#1" does not exist. (ignored)}}%
  \fi\:tmp}

\long\def\:dosort#1#2#3#4{%
  \begingroup%
    \def\:tmp{#2}%
    \ifx\:tmp\:numless%
      \let\:comp\:compnum%
      \let\:dogreat\:doswitch%
      \let\:doless\:donone%
    \else\ifx\:tmp\:numgreat%
      \let\:comp\:compnum%
      \let\:dogreat\:donone%
      \let\:doless\:doswitch%
    \else\ifx\:tmp\:alphless%
      \let\:comp\:compalpha%
      \let\:dogreat\:doswitch%
      \let\:doless\:donone%
    \else\ifx\:tmp\:alphgreat%
      \let\:comp\:compalpha%
      \let\:dogreat\:donone%
      \let\:doless\:doswitch%
    \else\ifx\:tmp\:asciiless%
      \let\:comp\:compascii%
      \let\:dogreat\:doswitch%
      \let\:doless\:donone%
    \else\ifx\:tmp\:alphless%
      \let\:comp\:compascii%
      \let\:dogreat\:donone%
      \let\:doless\:doswitch%
    \fi\fi\fi\fi\fi\fi%
    \BRANCHTYPES{#1}{\MAP{\TYPE}{%
      \expandafter\gdef\expandafter\::tmp\expandafter{\expandafter{\ME}}%
      \protected@edef\:tmp{#3}%  %%% LaTeX's \protect mechanism
      \global\expandafter\:ap\expandafter\::tmp\expandafter{\:tmp}%
      \aftergroup\:makenode}}%
    \setbox0=\vbox{%
      \gdef\:scnt{0}#4%
      \let\:bcnt\:scnt%
      \:bubblesort%
      \gdef\:sorted{}%
      \def\:bcnt{1}%
      \:buildsorted}%
      \gdef\:scnt{0}%
  \endgroup}
\def\:makenode{%
  \:count\:scnt%
  \advance\:count1%
  \xdef\:scnt{\the\:count}%
  \global\expandafter\let\csname\:scnt :ar\endcsname\::tmp%
  \gdef\::tmp{}}

\def\:doswitch{%
  \expandafter\let\expandafter\:tmp\csname\:fcnt :ar\endcsname%
  \global\expandafter\expandafter\expandafter\let\expandafter\expandafter%
    \csname\:fcnt :ar\endcsname\csname\:lcnt :ar\endcsname%
  \global\expandafter\let\csname\:lcnt :ar\endcsname\:tmp}
\let\:donone\relax

\long\def\:checksortarg#1{%
  \:gotrue%
  \def\:tmp{#1}%
  \ifx\:tmp\:numless%
  \else\ifx\:tmp\:numgreat%
  \else\ifx\:tmp\:alphless%
  \else\ifx\:tmp\:alphgreat%
  \else\ifx\:tmp\:asciiless%
  \else\ifx\:tmp\:alphless%
  \else%
    \:gofalse%
    \:typgenwarn{"#1" is not a valid sort option (ignored). Use one
      of: \:mb \:numless, \:numgreat, \:alphless, \:alphgreat,
      \:asciiless, \:asciigreat}%
  \fi\fi\fi\fi\fi\fi}
\def\:numless{num<}
\def\:numgreat{num>}
\def\:alphless{alpha<}
\def\:alphgreat{alpha>}
\def\:asciiless{ascii<}
\def\:asciigreat{ascii>}

\def\:compnum{%
  \ifnum\:first>\:second%
    \let\:doresult\:dogreat%
  \else\ifnum\:first<\:second%
    \let\:doresult\:doless%
  \else%
    \let\:doresult\:donone%
  \fi\fi}

\def\:compalpha{%
  \def\:comptemp{%
    \edef\:firstlett{\lccode\:firstlet}%
    \edef\:secondlett{\lccode\:secondlet}%
    \ifnum\:firstlett>\:secondlett%
      \let\:doresult\:dogreat%
    \else\ifnum\:firstlett<\:secondlett%
      \let\:doresult\:doless%
    \else%
      \ifnum\:firstlet>\:secondlet%
        \let\:doresult\:dogreat%
      \else\ifnum\:firstlet<\:secondlet%
        \let\:doresult\:doless%
      \else%
        \let\:doresult\:donone%
        \let\:tmp\:compstring%
      \fi\fi%
    \fi\fi}%
  \:compstring}

\def\:compascii{%
  \def\:comptemp{%
    \ifnum\:firstlet>\:secondlet%
      \let\:doresult\:dogreat%
    \else\ifnum\:firstlet<\:secondlet%
      \let\:doresult\:doless%
    \else%
      \let\:doresult\:donone%
      \let\:tmp\:compstring%
    \fi\fi}%
  \:compstring}

\def\:compstring{%
  \expandafter\:suckfirst\:first\:endsuck%
  \expandafter\:sucksecond\:second\:endsuck%
  \let\:tmp\relax%
  \ifx\:first\empty%
    \ifx\:second\empty%
      \let\:doresult\:donone%
    \else%
      \let\:doresult\:doless%
    \fi%
  \else%
    \ifx\:second\empty%
      \let\:doresult\:dogreat%
    \else%
      \edef\:firstlet{\expandafter`\:firstlet}%
      \edef\:secondlet{\expandafter`\:secondlet}%
      \:comptemp%
    \fi%
  \fi\:tmp}

\def\:endsuck{\:endsuck}

\def\:suckfirst{\futurelet\:tmp\::suckfirst}
\def\::suckfirst{%
  \ifx\:tmp\:endsuck\let\:tmp\:finishfirst%
  \else\ifx\:tmp\:sptoken\let\:tmp\:getfirstsp%
  \else\let\:tmp\:getfirstlet%
  \fi\fi\:tmp}
\def\:finishfirst#1\:endsuck{\def\:first{#1}}
\def\:getfirstsp#1 {\def\:firstlet{ }\:finishfirst}
\def\:getfirstlet#1{\def\:firstlet{#1}\:finishfirst}

\def\:sucksecond{\futurelet\:tmp\::sucksecond}
\def\::sucksecond{%
  \ifx\:tmp\:endsuck\let\:tmp\:finishsecond%
  \else\ifx\:tmp\:sptoken\let\:tmp\:getsecondsp%
  \else\let\:tmp\:getsecondlet%
  \fi\fi\:tmp}
\def\:finishsecond#1\:endsuck{\def\:second{#1}}
\def\:getsecondsp#1 {\def\:secondlet{ }\:finishsecond}
\def\:getsecondlet#1{\def\:secondlet{#1}\:finishsecond}

\def\:bubblesort{%
  \ifnum\:bcnt>0%
    \def\:fcnt{1}%
    \def\:lcnt{2}%
    \:bubbleloop%
    \:count\:bcnt%
    \advance\:count-1%
    \edef\:bcnt{\the\:count}%
    \let\:tmp\:bubblesort%
  \else%
    \let\:tmp\relax%
  \fi\:tmp}

\long\def\:getsecond#1#2\:delim{\def\:tmp{#2}}

\def\:bubbleloop{%
  \ifnum\:fcnt<\:bcnt%
    \expandafter\let\expandafter\:first\csname\:fcnt :ar\endcsname%
    \expandafter\let\expandafter\:second\csname\:lcnt :ar\endcsname%
    \expandafter\:getsecond\:first\:delim%
    \let\:first\:tmp%
    \expandafter\:getsecond\:second\:delim%
    \let\:second\:tmp%
    \:comp%
    \:doresult%
    \let\:fcnt\:lcnt%
    \:count\:lcnt%
    \advance\:count1%
    \edef\:lcnt{\the\:count}%
    \let\:tmp\:bubbleloop%
  \else%
    \let\:tmp\relax%
  \fi\:tmp}

\def\:buildsorted{%
  \ifnum\:bcnt>\:scnt%
    \let\:tmp\relax%
  \else%
    \expandafter\:build\csname\:bcnt :ar\endcsname%
    \:count\:bcnt%
    \advance\:count1%
    \edef\:bcnt{\the\:count}%
    \let\:tmp\:buildsorted%
  \fi\:tmp}
\def\:build#1{\expandafter\:buildsuck#1\:endsuck\gdef#1{}}
\def\:buildsuck#1#2\:endsuck{%
  \expandafter\gdef\expandafter\:sorted\expandafter{\:sorted\:i{#1}}%
  }


%%%%%
%% \SIFT{Foobar}{sift}{field}{value}{Datatype macros}{OPTION}
%%
\long\def\SIFT#1#2#3#4#5#6{\:typetest{#1}{%
  \:checksiftarg{#2}%
  \if:go%
    \:dosift{#1}{#3}{#4}{#5}%
    \def\:i##1{\:ap\:tmp{##1{#6}}}%
    \def\:tmp{\let\:tmp\empty}%
    \:sifted%
    \global\let\:sifted\relax%
  \fi%
  }\:tmp}


%%%%%
%% \MAKESIFT{Foobar}{sift}{field}{value}{Datatype macros}{NAME}
%%
\long\def\MAKESIFT#1#2#3#4#5#6{\:typetest{#1}{%
  \:checksiftarg{#2}%
  \if:go%
    \ifcsname#6:SIFT\endcsname%
      \:typgenwarn{"#6" reused as sifted list name.}%
    \fi%
    \:dosift{#1}{#3}{#4}{#5}%
    \expandafter\let\csname#6:SIFT\endcsname\:sifted%
    \global\let\:sifted\relax%
  \fi%
  }}


%%%%%
%% \USESIFT{NAME}{OPTION}
%%
\long\def\USESIFT#1#2{%
  \ifcsname#1:SIFT\endcsname%
    \def\:i##1{\:ap\:tmp{##1{#2}}}%
    \def\:tmp{\let\:tmp\empty}%
    \csname#1:SIFT\endcsname%
    \global\let\:sorted\relax%
  \else%
    \def\:tmp{\:typgenwarn{sifted list "#1" does not exist. (ignored)}}%
  \fi\:tmp}

\long\def\:checksiftarg#1{%
  \:gotrue%
  \def\:tmp{#1}%
  \ifx\:tmp\:equal%
    \def\:sift{\ifx\:first\:second\:gotrue\fi}%
  \else\ifx\:tmp\:notequal%
    \def\:sift{\ifx\:first\:second\else\:gotrue\fi}%
  \else\ifx\:tmp\:numless%
    \def\:sift{\let\:doless\:gotrue\:compnum\:doresult}%
  \else\ifx\:tmp\:notnumless%
    \def\:sift{\let\:donone\:gotrue\let\:dogreat\:gotrue\:compnum\:doresult}%
  \else\ifx\:tmp\:numgreat%
    \def\:sift{\let\:dogreat\:gotrue\:compnum\:doresult}%
  \else\ifx\:tmp\:notnumgreat%
    \def\:sift{\let\:donone\:gotrue\let\:doless\:gotrue\:compnum\:doresult}%
  \else\ifx\:tmp\:alphless%
    \def\:sift{\let\:doless\:gotrue\:compalpha\:doresult}%
  \else\ifx\:tmp\:notalphless%
    \def\:sift{\let\:donone\:gotrue\let\:dogreat\:gotrue\:compalpha\:doresult}%
  \else\ifx\:tmp\:alphgreat%
    \def\:sift{\let\:dogreat\:gotrue\:compalpha\:doresult}%
  \else\ifx\:tmp\:notalphgreat%
    \def\:sift{\let\:donone\:gotrue\let\:doless\:gotrue\:compalpha\:doresult}%
  \else\ifx\:tmp\:asciiless%
    \def\:sift{\let\:doless\:gotrue\:compascii\:doresult}%
  \else\ifx\:tmp\:notasciiless%
    \def\:sift{\let\:donone\:gotrue\let\:dogreat\:gotrue\:compascii\:doresult}%
  \else\ifx\:tmp\:asciigreat%
    \def\:sift{\let\:dogreat\:gotrue\:compascii\:doresult}%
  \else\ifx\:tmp\:notasciigreat%
    \def\:sift{\let\:donone\:gotrue\let\:doless\:gotrue\:compascii\:doresult}%
  \else%
    \:gofalse%
    \:typgenwarn{"#1" is not a valid sift option (ignored). Use one
      of: \:mb \:equal, \:notequal, \:numless, \:notnumless,
      \:numgreat, \:notnumgreat, \:alphless, \:notalphless,
      \:alphgreat, \:notalphgreat, \:mb \:asciiless, \:notasciiless,
      \:asciigreat, \:notasciigreat}%
  \fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi}
\def\:equal{=}
\def\:notequal{!=}
\def\:notnumless{num<=}
\def\:notnumgreat{num>=}
\def\:notalphless{alpha<=}
\def\:notalphgreat{alpha>=}
\def\:notasciiless{ascii<=}
\def\:notasciigreat{ascii>=}

\long\def\:dosift#1#2#3#4{%
  \begingroup%
    \BRANCHTYPES{#1}{\MAP{\TYPE}{%
      \protected@edef\:first{#2}%  %%% LaTeX's \protect mechanism
      \protected@edef\:second{#3}%  %%% LaTeX's \protect mechanism
      \let\:donone\relax%
      \let\:dogreat\relax%
      \let\:doless\relax%
      \:gofalse%
      \:sift%
      \if:go%
        \expandafter\:addsift\ME\:endsuck%
      \fi}}%
    \gdef\:sifted{}%
    \setbox0=\vbox{#4}%
  \endgroup}
\long\def\:addsift#1\:endsuck{%
  \:singletst#1\:delim%
  \ifx\:tmp\empty%
    \expandafter\gdef\expandafter\:sifted\expandafter{\:sifted\:i#1}%
  \else%
    \expandafter\gdef\expandafter\:sifted\expandafter{\:sifted\:i{#1}}%
  \fi}

%%%%%
%% reserving TeX registers
\newcount\:count
\newtoks\:toks

%%%%%
%% formatting of error and warning messages
\def\:mb{^^J\space\space}  %% linebreak in error/warning text
\def\:err{\errmessage{datatype error}}
\def\:typerr#1#2{\immediate\write16{%
  ^^J! datatype \MYTYPESTRING\space error: #1%
  ^^J? #2%
  ^^J!punting LaTeX!}%
  \batchmode\@@end}
\def\:typgenerr#1#2{\scrollmode\:err\immediate\write16{%
  ^^J! datatype error: #1%
  ^^J? #2%
  ^^J!punting LaTeX!}%
  \batchmode\@@end}
\def\:typwarn#1{\immediate\write16{%
  ^^J! datatype \MYTYPESTRING\space warning: #1%
  ^^J}}
\def\:typgenwarn#1{\immediate\write16{%
  ^^J! datatype warning: #1%
  ^^J}}

%%%%%
%% some "standard" errors
\def\er:tblank{\:typgenerr{There is no "" (empty string) datatype.}
  {A string of some sort is expected.  Don't leave the typestring
  for\:mb a datatype blank.}}

\def\er:tunknown#1{\:typgenerr{Datatype #1 isn't declared.}
  {There is no datatype #1 declared.  Use \string\DECLARETYPE{#1}
  \:mb(or \string\DECLARESUBTYPE) to declare it.}}

\def\er:funset#1{\:typerr{\string#1 used but not \noexpand\s in
  \expandafter\string\MYCOMMAND.}{\string#1 must either be set by
  \noexpand\s or have a default declared by \:mb "\noexpand\FD
  {\string#1} { default }" before it is used.}}

%%%%%
%% handling of null cases, "reserved" commmand names, etc.
\gdef\:lvl{0}
\newif\if:go
\:gofalse

\gdef\:d{}
\gdef\:t{}
\gdef\:p{}
\gdef\:ct{}
\gdef\:ca#1{}
\gdef\:pdo{}
\gdef\:phd{}
\gdef\:phh{}
\gdef\:pre{}
\gdef\:pst{}
\gdef\:do{}
\gdef\:hd{}
\gdef\:hh{}
\gdef\:rdo{}
\gdef\:rhd{}
\gdef\:rhh{}
\gdef\:lst{}
\gdef\:add#1{}

\def\:nocontext#1{\def#1{\:typgenerr{Don't use \string#1 outside the
  scope of a DataType.}{It has no context.}}}

\:nocontext\MYCOMMAND
\:nocontext\ME
\:nocontext\MYTYPESTRING
\:nocontext\MYPARENTSTRING
\:nocontext\MYMAP
\:nocontext\PARENT
\:nocontext\PARENTMAP
\:nocontext\PARENTSURFACEMAP
\:nocontext\ADD
%\:nocontext\RESET
\:nocontext\F
\:nocontext\FD
\:nocontext\FS
\:nocontext\s
\:nocontext\rs
\:nocontext\append
\:nocontext\prepend


%%%%%
%%  Returning ":" to its default behavior, so it can no longer be
%% used in TeX command names.
\catcode`\:12\relax


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
